The quality of paper or paperboard can be improved by, among other ways, treating the surface of a paper or paperboard web with a suitable chemical agent. As market demands require paper to exhibit higher levels of brightness, optical whitener or optical brightening agent (OBA), is added at exorbitant amounts to increase the amount of light reflectance, or brightness measured in a sheet. The OBA works by absorbing UV light and re-emitting it at visible light wavelengths, measured in a specified reflective range. In these applications, the starch acts as a UV light filter when it is yellow colored, and prevents complete activation of the OBA molecule for its intended purpose of increasing brightness.